Recently, along with the flourishing developments of the communication devices, needs for antennas installed to the communication devices increase. In addition, the developments of communication devices become diverse, so do the antennas.
U.S. Pat. No. 8,547,283 recites a multiband antenna and method for an antenna to be capable of multiband operation. Please refer to FIG. 1. The multiband antenna 90 includes a first metal portion 91, a second metal portion 92, and a third metal portion 93. A capacitively-coupled portion 94 is formed between the first metal portion 91 and the second metal portion 92, and an inductively-coupled portion 95 is connected between the second metal portion 92 and the third metal portion 93. The first metal portion 91 and the second metal portion 92 enable the multiband antenna 90 to generate a first operating band. The first metal portion 91, the second metal portion 92, and the third metal portion 93 enable the multiband antenna 90 to generate a second operating band.
However, the first metal portion 91, the second metal portion 92, and the third metal portion 93 of the multiband antenna 90 are respectively disposed on the same substrate. As a result, the value of the capacitively-coupled portion 94 and the value of the inductively-coupled portion 95 are restricted, and the antenna bandwidth is restricted.